Double-hearth heating-furnace.



No. 729,092. PATENTED MAY 26, 1903. P. PATTERSON. I

DOUBLE HEARTH HEATING FURNACE.

APPLICATION FILED JAN. 23, 1902.

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. No. 729,092 PATENTED MAY 26, 1903.

P. PATTERSON.

DOUBLE HBARTH HEATING FURNACE.

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%W/M@ y ZEZZ? UNTTEE STATES Patented May 26, 1903.

PATENT OFFICE.

PETER PATTERSON, 'OF MOKEESPORT, PENNSYLVANIA, ASSIGNOR TO NATIONAL TUBE COMPANY, OF PITTSBURG, PENNSYLVANIA, A COR- PORATION OF NEW JERSEY.

DOUBLE-HEARTH HEATING-FURNACE.

SPECIFICATION forming part of Letters Patent No. 729,092, dated. May 26, 1903.

Application filed January 23, 1902. Serial No. 90,975. (No model.)

To all, whom it may concern:

Be it known that LPETER Pmrnnsoma resident of McKeesport, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Double-Hearth Heating-Furnaces; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to furnaces for heating tube-plates, skelps, or other blanks, and more especially to heating tube-plates preparatory to bending the same into skelps, although the invention is not confined to this, but is equally applicable to the heating of blanks of any character.

In furnaces for bending plates into skelp the capacity of the bending dies or rolls is limited by the capacity of the furnace, or, in other words, the furnace cannot heat the plates sufficiently fastto keep the dies or rolls employed continuously. This drawback also afiects the welding-furnaces, which may remain idle for a considerable time at intervals waiting for skelp to be drawn. During these delays the crews of course are idle, and as a consequence the output per furnace is limited and the cost of the product proportionately increased.

The object of my invention is to overcome the aforesaid drawbacks and to provide a furnace having a greater capacity, whereby the bending or welding apparatus can be keptin more continuous operation, the output increased, and the cost thereof correspondingly diminished.

To this end my invention consists, generally stated, in providing a plurality of hearths for the furnace, preferably one above the other, on both or'all of which plates, skelps, or other blanks can be heated simultaneously.

In the accompanying drawings, Figure 1 is a cross-section through my improved furnace. Fig. 2 is a plan view of the same. Fig. 3 is a longitudinal section thereof. Figs. 4. and 5 are plan and sectional views, respectively, of the tiles forming the upper hearth; and Figs. 6 and 7 are top and side views, respectively, of the pillars for supporting the same.

The furnace shown is an ordinary gas heating-furnace of the regenerative type, and it is provided with the side walls 1, roof 2, and

front and rear end walls 3, the latter being provided with suitable openings 4, through which the plates, skelp, or other blanks may be charged into the furnace at one end and withdrawn therefrom at the opposite end. This is the preferred construction of furnace; but my invention is not limited in this particular, as it is equally applicable to a furnace wherein the withdrawing takes place at the same end as the charging. The furnace illustrated is provided along its sides with the gas-ports 5 and air-ports 6, said ports being alternately arranged, as shown, and being supplied with heated air and gas, which is admitted on one side of the furnace, passes up into the combustion-chamber 7, and the waste products of combustion pass out through the ports on the opposite side of the furnace and through the regenerators, thereby heating the latter, said air and gas being periodically reversed, as is common in regenerative furnaces and as will be understood without further description. My invention, however, is not limited to aregenerative furnace nor to one having the air and gas ports arranged as shown, as it may be applied to any other type of heating-furnace.

The furnace is provided with the main hearth S and above the same with the secondary hearth 9, the latter being supported above the main hearth by suitable means which will permit the free circulation of the flame and heated products underneath the secondary hearth and above the main hearth,such means being shown as pillars 10. The main hearth is shown as elevated somewhat above the outlets of the air and gas ports in order to insure the circulation of a proper amount of flame and heated products underneath the secondary hearth and over the main hearth to heat the plates, skelp, or other blanks placed upon the latter. As a further means to insure such circulation underneath the secondary hearth the sloping sides 11 of the main hearth are provided with grooves or passages 12, which lead up under the secondary hearth and help to draw or guide the air and gases or flame and heated products in between the two hearths. These grooves or passages 12 are preferably arranged as shownthatlis, one for each pair of air and gas ports so as to guide substantially equal proportions of air and gas or flame therefrom in between the two hearths.

The upper or secondary hearth may be constructed in any preferred manner; but I prefer to construct thelsame of separate tiles 13, of fire-brick or other refractory material, these tiles being each provided on one end with a projecting tongue 14 and at the opposite end with a corresponding recess 15 for receiving the tongue 14 of the next adjacent tile, so that by this means the tiles are locked together to form a substantially unbroken bed. The tiles at each corner are provided at their lower sides with a cut-away portion 16, and the pillars 10 are provided at their upper ends with square projectious which fit into depressions formed by the cut-away portion 16 at the meeting corners of four tiles, thereby holding the tiles in place. The pillars 10 are shown with square bases which are set down into the main hearth, although this is not necessary. The tiles on the edges or the sides of the secondary hearth are provided with the flanges 18, projecting slightly above the upper face of said hearth.

In the use of the furnace illustrated it is heated in the usual way by the air and gas coming from the ports 5 and 6, and the air and gas are reversed periodically, as is now the practice. Plates, skelps, or other blanks 19 are charged into the furnace onto the main hearth 8 between the pillars 10 and also onto the secondary hearth 9, as shown in Fig. 1, and all of these plates or blanks are being heated simultaneously in the furnace. By the double-hearth arrangement shown the capacity of the furnace is almost, if not quite, doubled-that is, if with a single hearth the furnace were capable of containing six plates or blanks with the double hearth shown six such plates or blanks will be supported upon the upper hearth and five upon the lower hearth, as shown. If itis desired to still further increase the capacity of the furnace, still another hearth may be supported above the hearth 9, and in this way a furnace of sufficient capacity to keep the bending or other mechanism in continuous operation is insured.

By the term hearth as used herein I do not wish to limit myself to an unbroken floor,

such as shown at 9, but to include any means for supporting the plate or other blank while being heated in the furnace.

What I claim as my invention, and desire to secure by Letters Patent, is

1. A heating-furnace having a heatingchamber, a plurality of hearths in said chamber one directly above the other, and air and gas ports leading to said chamber and arranged so as to provide the products of combustion and deliver the same at substantially equal temperatures into the space above each of said hearths.

2. A heating-furnace having a heatingchamber, a main hearth therein, supports rising from said hearth, a secondary hearth on said supports, and air and gas ports leading to said chamber and arranged to divide the products of combustion and deliver the same at substantially equal temperatures into the space above each of said hearths.

3. A heating-furnace having a heatingchamber, a main hearth therein, air and gas ports arranged at the side of said hearth, and a secondary hearth in said chamber above the main hearth, said secondary hearth being constructed to leave open spaces above the air and gas ports.

4. A heating-furnace having gas and air ports located at both sides thereof, a main hearth between said ports and above the inlets thereof, and a secondary hearth supported above the main hearth.

5. A heating-fu rnace provided with gas and air ports at both sides thereof, a main hearth between said ports and on a plane above the inlets thereof, grooves or passages leading from the gas and air ports to the main hearth,

and a secondary hearth supported above said PETER PATTERSON.

Witnesses:

ROBERT C. TQTTEN, RoBT. D. TOTTEN. 

